The present inventive concept relates to a method for driving a nonvolatile memory device having memory cells which include, for example, a resistive element.
Certain types of nonvolatile memory devices utilize a material (herein a resistance material) having a programmable resistance characteristic to store data. Examples of such devices include phase change random access memories (PRAMs) or phase change memories (PCMs), resistive RAMs (RRAMs), magnetic RAMs (MRAMs), and the like. Depending on the type of memory device, the resistance material may be a phase change material such as a chalcogenide alloy (in the case of a PRAM), a variable resistance material (in the case of an RRAM), a magnetic tunnel junction (MTJ) thin film (in the case of an MRAM), and the like.
In the case of a phase change material, for example, the material may be changed to a relatively crystalline state or a relatively amorphous state by selective controlling heating and subsequent cooling of the material. The phase change material in the crystalline state exhibits a lower resistance than in the amorphous state. In conventional nomenclature, the low resistance crystalline state is referred to as a set state, and the high resistance amorphous state is referred to as a reset state.